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Extensive research has been conducted on the development of Slurry Infiltrated Fiber Concrete SIFCON and its characteristics. Fly ash was used as a binder in this study, and two different kinds of steel fibers—micro and hooked steel fibers—were used in the mortar in variable ratios (0, 6, 12, and 18) to examine the properties of SIFCON geopolymer concrete. The optimization of the geopolymer slurry texture, compression strength, hardness, ultrasonic pulse-velocity, elastic modulus (dynamic) (Ed), shear modulus (dynamic) (Gd), and the logical correlation among non destructive testing (NDT) (RN and UPV) and compression strength were all examined. The test outcomes demonstrated impoved characteristics, such as a 26.1% increase in compressive strength when 12% micro fiber of steel was used. The value of ultrasonic pulse velocity (UPV), which includes shear pulse velocity (Vs) and longitudinal pulse velocity (Vl) showed increases of 33.70% and 27.50% respectively, with the addition of 12% micro fiber of steel. Insertion of 12% hooked-end steel fiber, however, produced ideal rebound number readings. [ABSTRACT FROM AUTHOR]

In this research, we examine how polymer-coated concrete and concrete coated with polymer and steel reinforced fibre fare in terms of compressive strength. Steel fibres make about 3 percent of the mix for casting the polymer-coated concrete cubes. For a power analysis with known hypotheses, significance levels, sample sizes, and expected values, the final sample size is 36 people (18 in each group). In this study, both a control and an experimental group participated. According to Clincalc, a sample size of 18 would have 80 percent pretest power at a 0.05 level of significance. The statistical programme SPSS was used to record and analyse the outcomes of 18 tests conducted on both unreinforced and steel-reinforced concrete. SPSS-V26 programme found significant differences between polymer coated plain ordinary concrete and polymer coated concrete with 3% steel fibre at the p=0.045 level. Polymer-coated concrete with a steel-fiber volume fraction of 3 percent was found to have significantly greater compressive strength than polymer-coated plain conventional concrete within the scope of this investigation. [ABSTRACT FROM AUTHOR]

The goal of this study is to determine how much of an effect glass fibre has on the compressive strength of M20 concrete. There are two groups in this investigation, and 18 samples have been prepared for each. Group 1 consists of your standard M20 concrete, whereas Group 2 features M20 concrete that has been strengthened with glass fibres. CLINICAL software was used to determine the sample size based on values taken from previously published studies. Several tools and resources were used to get the samples ready for analysis. The independent sample T-test, performed in SPSS version 21, shows that the addition of polymer coating to cured fiber-reinforced M20 grade concrete with GGBS slag (20 percent) significantly raises the concrete's compressive strength. According to the results of the compressive testing machine, the increase in strength is 17.435 percent. Table 6 shows that the significance of these occurrences was 0.034. (p0.05). The M20 grade glass-reinforced concrete had a standard deviation of 1.42683, as shown in table 5. Based on the results of this experiment, it can be said that M20 grade concrete that has been reinforced with glass fibres has higher compressive strength than regular M20 grade concrete. [ABSTRACT FROM AUTHOR]

As the rate of usage of concrete continues to increase, the acquisition of the required raw materials from nature for the process of concrete production is also increasing. Using waste materials instead of, or even as a partial replacement for, concrete ingredients might reduce the need to extract raw materials from nature, and this article thus offers a review of previous work on the use of various types of waste glass (fluorescent lamps, packaging glass, food glass, medical glass, door glass, window glass, and coloured and transparent flat glass) as a partial replacement for cement in concrete to study the effects of such replacement on the fresh and mechanical properties of the resulting concrete. The results suggest that the optimum range of use for waste glass replacement to provide properties comparable to those of the control mix is between 10 and 15%. Additionally, the influence of such replacement on the fresh and mechanical properties of concrete is dependent on both particle grading and chemical composition according to the reviewed data. In particular, using 10% waste glass from crushed building waste glass increases compressive strength by 4.6% as compared to the control mix, whereas using 10% heavyweight waste glass causes a 5.2% reduction in the comparative compressive strength. [ABSTRACT FROM AUTHOR]

In structural engineering, composite construction occurs when two different materials are connected together so tightly that then operate as a single unit. The most common and important combination of construction materials currently is steel-concrete. This study was thus conducted to investigate the strength and behavior of the new shear connector created in steel-concrete composite systems. In such systems, the shear stirrups of the reinforced concrete beam are used as shear connectors, being passed through holes drilled in the web of inverted steel T-section that exists at the soffit of the beam. The program followed by this study thus tested a new arrangement of push-out specimens proposed for this purpose. A total of fifty-six push-out specimens were fabricated and tested to investigate the effect of multiple parameters on the shear strength and slip capacity of the shear connectors. The parameters studied in this experimental investigation were thus specimen dimensions (length and width), the diameter of the stirrups (shear connector), the number of connectors per specimen, concrete strength, type (size) of T-section, and shape of specimen. The experimental tests showed that the strength of connector is influenced significantly by various parameters. The strength of connector decreases with an increase in the number of connectors in the specimens, with the reduction in strength reaching 15% when three connectors are used instead of one. The strength of the connector increases with increases in the shear connector diameter, specimen width, and concrete strength, with such increase reaching 63%, 49%, and 25% respectively. The other parameters have little effect on the maximum shear strength of connector, however. [ABSTRACT FROM AUTHOR]

As a non-homogenous material, the characteristic tests of concrete in the laboratory do not always represent the quality and the size of the actual condition in the construction field. The heterogenous characters have an essential role that evokes the variability of concrete properties. In a case requiring high accuracy, such as concrete damage or crack modelling, heterogeneities should be considered. The objective of this research is to apply the variability of mechanical properties to numerical simulation in a simple cubical sample of Oil Palm Shell (OPS) concrete. By using a statistical approach, the variability is captured by a random field, in which its random variables are generated by implementing The Turning Band Method (TBM) in a finite element code-based application, Cast3M. Mazars damage model is chosen to govern the concrete damage behavior. The simulation is performed by varying a random field meshing size and correlation length, and the sample is compressively loaded. The modelling results are compared to the previous laboratory test conditions. By considering the concrete heterogenous nature, the damage pattern is varied, in which the modelling using smaller mesh exhibited a failure that was relatively close to the experimental study. The damage behavior of finer mesh showed more variation with the cracks accumulated in certain parts of the sample's sides, whereas it is dominantly spread on the whole top section in coarser mesh. Moreover, the modification of the mesh dimension and correlation length indicated that it has considerable effect on the concrete damage behavior and strength estimation. [ABSTRACT FROM AUTHOR]

This study summarized the recent achievement in developing fiber reinforced geopolymer concrete. The factor of replacing Ordinary Portland Cement (OPC) which is due to the emission of carbon dioxide where pollutes the environment globally is well discussed. The introduction towards metakaolin is presented. Besides, the current research trend involved in geopolymer also has been reviewed for the current 17 years to study the interest of researchers over the world by year. Factors that contribute to the frequency of geopolymer research are carried out which are cost, design, and the practicality of the application for geopolymer concrete. Besides, the importance of steel fibers addition to the geopolymer concrete is well discussed. The fundamental towards metakaolin has been introduced including produce by calcined kaolin, calcined temperature, chemical composition, geopolymerization process, and other properties. Alkali activators which are mixing solution between sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) have been reviewed. The mechanical properties of fibers reinforced metakaolin-based geopolymer concrete which is compressive and flexural are thoroughly reviewed. The compressive and flexural strength of fiber-reinforced metakaolin geopolymer concrete shows some improvement to the addition of steel fibers. [ABSTRACT FROM AUTHOR]

Presently, seashell waste is a raw material that is easily available and is an attraction as a material to be recycled to replace materials in concrete mixes such as fine aggregates, coarse aggregates and cement. Previous study found that the seashell waste has demonstrated properties that will help to increase the strength of concrete if added as aggregate as the strength closely equal with aggregate. Other than that, the content of calcium carbonate that can be produced from the shell can contribute to the overall strength of concrete mixture. Moreover, the depletion of natural resources such as aggregate in construction due to the high demand has been stressing which led to more environment friendly usage of material for construction. Therefore, this paper explores the mechanical and physical properties of seashell waste as a partial replacement for fine aggregate. About 36 cube samples, 18 prism samples and 15 control samples were casted in concrete grade M30 with the replacement percentage of 60%, 70%, 80% seashell as fine aggregate. The outcome shows that highest strength for compressive strength and flexural strength test on 70% of replacement seashell as fine aggregate in concrete. [ABSTRACT FROM AUTHOR]

The high strength of concrete required a lot of cement content to increase its strength but not for the anti washout concrete (AWC) or underwater concrete (UWC). AWC will face another problem which is higher cement content could make the segregation to occur. This segregation process will give bad impact to the strength of the AWC. This research studied on four different cement content to examine: 450 kg/m3, 500 kg/m3, 550 kg/m3 and 600 kg/m3 towards its fresh and hardened properties of concrete. Superplasticizer is used as water reducing agent in the mix proportions to achieve high strength and self-consolidated concrete. Apart from that, there are two types of concrete samples produced, the air sampling concrete and underwater sampling concrete which have the same mix proportion. The overall results show a good correlation between the cement content in the mix and the strength of the air sampling concrete achieved. However, anti washout concrete having issues which is segregation. This segregation had affected the strength of the concrete. In conclusion, Anti washout concrete shows that optimal cement content without any viscocity modifying agent (VMA) is at 550 kg/m3. [ABSTRACT FROM AUTHOR]

Geopolymer Concrete (GPCs) is a novel type of concrete that uses an inorganic alumina silicate binder system rather than the hydrated calcium silicate binder system, which is activated by alkaline liquids. Fly ash is the primary ingredient used to activate the geopolymerization process, as well as to substitute traditional Portland cement. The sole difference between this concrete and standard Portland cement concrete is the binding agent. Sodium hydroxide and sodium silicate solutions were used to activate the substance in fly ash. The geopolymer has the advantages of rapid strength increase, no need for water curing, excellent mechanical and durability features, and is an environmentally safe and sustainable alternative to OPC-based concrete. The manufacture of Portland cement, in particular, results in the release of air pollutants, resulting in environmental pollution in the construction industry. It cuts CO2 emissions by 80-90 percent. This research is to consolidate on the study on characterization and strength of fly ash based geopolymer rigid pavement through compressive strength, water absorption and density. From the results, it is concluded that when the solid to liquid ratio increased, compressive strength and the density will be increased due to the characteristics and properties of the geopolymer concrete however decrease in water absorption. [ABSTRACT FROM AUTHOR]

Research has been conducted on adding a mixture of Polyethylene Terephthalate (PET) and Coconut Fiber Ash (CFA) as a substitute for fine aggregate to see the characteristics of composite concrete. Variations were made to increase the weight percentage of PET by 3%, 5%, and 8% and use CFA by weight percentage of 5%, 10%, and 15% to replace the fine sand aggregate. This study uses a standard concrete mix design by SNI 03-2834-2000, which consists of sand, stone, cement, and water. The test object is cylindrical concrete with dimensions of 20 cm in height and 10 cm in diameter. The tests carried out are concrete density test, compression test, split tensile test, and analysis of the rule of the mixture of composite materials. This test was carried out when the concrete was 28 days old. The test analysis found that the more addition of PET and CFA to the concrete will result in a reduction in compressive strength, split tensile strength, and elastic modulus of concrete. The best value occurred in the percentage of the weight of the mixture of PET 3% and CFA 5% resulting in a concrete compressive strength of 19.48 MPa, a split tensile strength of 6.86 MPa, and an elastic modulus of 19,993 GPa. [ABSTRACT FROM AUTHOR]

This paper presents an experimental investigation into the behavior of a composite concrete slab encasing a steel castellated girder under four point loads. Five RC(Reinforcement Concrete) specimens have been considered in the experimental tests with a cross-section dimension of 125 mm x 500 mm and a length of 1500 mm. The testing procedure additionally provided for the fabrication of I-section steel beams with a 50% castellation ratio. One specimen has been represented by the specimens to be the reference specimen, which have an encasing ratio of 0% and are with shear connectors. Two variables have been considered in the experimental tests: the percentage of encasing (0, 20 and 40%) and the presence of shear connectors. The deflection at the center of the beam, first crack; load-rotation relationships; effects of encasing ratio; and bond slip were studied. The test results show that it was determined that the ultimate load capacity of 20% encasing (with and without studs) decreased from the reference specimen by 17.5% and 14.4%, respectively. Whereas, in comparison to reference specimens, ultimate load increases by about 5% for 40% of encasing with studs. The cause that the concrete penetrates through the hole on the web. On the other hand, the extensive usage of castellated steel beams as structural members has led to several investigations into their structural behavior. Castellated beams have been shown to be effective for longer, moderately loaded spans when deflection governs the design. [ABSTRACT FROM AUTHOR]

At present various under-rail designs made from different materials are used on railways worldwide. As the national requirements for railways are becoming stricter due to growing traffic speeds, axle loads, and loading, the improvement of under-rail structures and materials in relation to these requirements is an urgent task. The study presents an analytical review of literature data on the types of railway track substructures and track structure materials used in Europe and worldwide, features of construction and production technology of wooden, glued timber, reinforced concrete, metal, composite sleepers, their standardized characteristics (strength, frost resistance, cracking resistance, durability, electrical resistance) and test methods for their determination, peculiarities of interaction with ballast. The analytical review shows that many disadvantages of concrete sleepers reinforced with composite reinforcement can be overcome. Their advantages include high corrosion resistance of the reinforcement, which allows a rational approach to the assignment and provision of crack resistance of sleepers. An analysis of the mechanism of electric current flow through a concrete sleeper was carried out. It was shown that replacement of steel wire reinforcement with non-electric composite reinforcement will make it possible to increase the electric strength of a sleeper, to reduce the current flows and electrical corrosive phenomena even for the operation of a sleeper with cracks. As a result of the calculations and analysis of the stress-strain state of sleepers performed using the finite element method, it was found that sleepers reinforced with steel wire and composite reinforcement are subject to the same compressive strength. Reducing the pre-stressing force of the composite reinforcement even to the point of being completely eliminated leads to an increase in tensioning forces and cracked sleepers, but does not lead to concrete crumbling in the stiffened areas. [ABSTRACT FROM AUTHOR]

Concrete is a building material obtained by mixing cement, water and a ratio in an appropriate ratio. As the cost of cement rises day by day, the need for building materials and other essentials to keep up with the growing population is increasing. Therefore, it is necessary to be aware of other binding materials which will replace the cement partially or fully. Building rubble, in this case coconut fiber ash, creates pollution in environment. Coconut fiber is collected, moisture content was removed and roasted in an open area. After that, the fiber disintegrates into ash powder. The ash powder is collected and processed with a 150 micron filter. Concrete blocks are poured and aged for 7, 14, and 28 days, using 0, 5, 10, and 15 percent instead of cement ash and adding 3 times the weight of the cement to random carp. The results show that concrete performance decreases with increasing CFA content and compressive strength increases with healing, but decreases with increasing CFA content. The introduction of coir to the cement has notably improved many of the technical properties of concrete in terms of compressive strength, durability and flexibility. [ABSTRACT FROM AUTHOR]

Geopolymer concrete (GPC) is the most predominant alternate for cement concrete in construction industry which can highly reduce the CO2 emission by the cement production. Self-Compacting Concrete (SCC) is also the growing technology that can help to pour the concrete in congested reinforcement sections. The effort is initiated to utilize the GGBS and Silica Fume (SF) as binders to create the Self Consolidating GPC (SCGC). GGBS based geopolymer concrete lacks in rapid setting and sticky nature with the formulation of calcium silicate hydrate gel. Silica fume has most finer particles and it is used to replace the GGBS at 0 to 100 percent at 10 percent increment levels. The impact of various replacement levels of SF with GGBS on the rheology and mechanical behaviour are assessed. The findings indicate that increasing the replacement percentage of silica fume enhances flow properties due to the presence of finer particles that contribute to fluidity. However, higher silica fume percentages lead to a reduction in hardened properties. Notably, the mixture comprising 70 percent GGBS and 30 percent silica fume achieved a compressive strength of 39.8 MPa, which closely approaches the compressive strength of the all GGBS mixture. This blend, considered optimal, exhibited improved flow properties alongside its notable compressive strength performance. Hence the mix with 70 percent of GGBS and 30 percent of silica fume can choose as optimum mix for the production of self compacting geopolymer concrete with nominal strength. [ABSTRACT FROM AUTHOR]

The need for concrete is growing rapidly every day and cement is utilized to satisfy the requirement for development of infrastructure. The manufacturing of cement products generates a massive concentration of carbon dioxide (CO2) that impacts the ecosystem and surroundings, creates pollution as well as hazardous to human beings. In an effort to minimize the demand for cement and CO2 emission, in this study, alternating cementitious ingredients such as Ground granulated blast furnace slag (GGBFS) and silica fume (SF) were utilized. In this study, NaOH and Na2SiO3 were used to generate ground granulated blast furnace slag based geopolymer concretes that contained various proportions of silica fume, which were then cured at room temperature. Rheological, hardened, and durability properties were investigated. NaOH (14M) and Na2SiO3 were utilized as alkaline solutions to activate the geopolymerization. The findings indicate that the incorporation of SF increased the compressive, splitting tensile and flexural strength of geopolymer concrete. The geopolymer concrete has been observed highly reliable in the existence of 2 percent of sulphuric acid, 5 percent of sodium sulphate and 5 percent of sodium chloride. [ABSTRACT FROM AUTHOR]

The innovation and developments in concrete technology requires the concrete technologist to tailor the mix design of concrete to suit the strength and durability requirements. Modification of concrete is the age-old practice as the normal concrete exhibits drawbacks in terms of durability and flow ability. Several materials are being used for repairs of concrete however; epoxy is used for bonding concrete and also as a repair material confidentially by engineers undisputedly. The addition of epoxy resin to the concrete improves strength, adhesion, and chemical resistance of concrete. Literature and factual figures indicate that even high-performance concrete exhibited distress and deterioration well before reaching their designed service life due to aggressive exposure conditions. Hence there has been a continues technological investigations from 1960 to bring phenomenal changes in normal concrete with the addition of polymeric materials so as to modify ordinary concrete to modern concrete with improved performance in terms of strength and durability. Micro concrete is being used confidently as a repair material by engineers with partial modification by adding flyash, GGBS, polymers and epoxy along with micro aggregate and cement, specially wherever there is a problem of curing and penetration of mortar in inaccessible areas in case of damaged concrete structure. This paper presents a critical review of the development in epoxy modified concrete and micro concretes as value added material in concrete technology. [ABSTRACT FROM AUTHOR]

A low concrete compressive strength is a dominant problem in non-engineered buildings because unskilled workers carry out the concrete manufacturing process, resulting in poor quality. The poor concrete compressive strength causes a low bond to the steel reinforcements, leaving the beam and column elements prone to destruction, especially when receiving earthquake loads. This study numerically simulates the influence of concrete compressive strength on the seismic performance of reinforced concrete portals using ATENA software. The reinforced concrete portal model comprises columns with 150 mm x 150 mm cross-section and 2500 mm high, and a beam of 150 mm x 200 mm cross-section and 3000 mm length. Both columns and beam are reinforced with longitudinal and stirrup reinforcement 4D10 and ø6-200 mm, respectively. There are three variations of the models, comprising models with the quality of concrete according to SNI 2847 for earthquakes design with f'c 21 MPa, the quality of concrete for general use f'c 17 MPa, and the quality of concrete representing non-engineered buildings with f'c 10 MPa. The structural performance analysis includes load capacity, displacement, pattern and width of cracks, stress patterns of concrete, and reinforcement. Based on the results of the ATENA analysis, reducing the concrete from 21 MPa to 10 MPa will reduce the capacity of the specimen model by 10.01%, reduce the energy dissipation capability by 3.91%, and change the collapse pattern from column element to beam-column joint element. [ABSTRACT FROM AUTHOR]

Onyx waste from onyx material crafts is utilized as coarse aggregate in concrete mixtures. Onyx waste concrete and standard concrete have different characteristics and rheological properties when viewed from the physical and mechanical properties of the aggregates that form them. Rheological studies of fresh concrete in the onyx waste concrete mixture were carried out by comparing fresh concrete's workability performance and rheological parameters between standard concrete and onyx waste concrete. Concrete slump, slump flow, and compaction factor tests are a series of workability tests carried out to compare the performance of fresh concrete and compressive strength testing to determine the resulting compressive strength. The results showed that the performance or workability of fresh concrete increased with replacing coarse aggregate with onyx stone waste. The slump value increased by 42.42%, the slump flow test increased by 25.974%, 7.142%, and 13.889%, and the factor test compaction increased by 3.557%. Analysis of rheological parameters showed that replacing coarse aggregate with onyx waste reduced the viscosity and yield stress values. The viscosity value and yield stress decreased by 60.261% and 45.970%, respectively. Therefore, it can be concluded that the onyx waste concrete is more manageable to deform than the normal concrete. The compressive strength produced by the onyx stone waste still meets the requirements of the compressive strength criteria as structural concrete. [ABSTRACT FROM AUTHOR]

The study aims to produce concrete using various percentages of hypo-sludge ash (HAS) in place of cement. The waste paper sludge ash is composed of magnesium oxide and calcium oxide. Therefore, it can be tested as an innovative cement replacement, providing a solution for traditional concrete. For this study, the various proportions of ash used are 5%, 10%, and 15% by weight of cement. The mixed design carried out was as per the Indian standard code. The ingredients used for concrete making are cement, aggregates, hypo sludge ash (HSA), superplasticizer, and water. A test mix was carried out to check the behaviour of a concrete mix, and its physical and hardening properties were checked. Cube samples were cured for 3, 7, 14, and 28 days to check hardening properties. Experimental analysis shows that by replacing 5% cement with HSA, the strength results obtained are close to the reference concrete. [ABSTRACT FROM AUTHOR]

Research on the compression behavior of concrete has been widely carried out, on the other hand, information about the behavior of concrete in tension was limited. The existing concrete tension tests are the splitting, direct tensile, and rupture tests. These methods provide information on the tensile strength of concrete through concrete tension stiffening tests. This paper aims to elaborate on the experimental study to develop and construct the equation of concrete tensile strength based on the tension stiffening effect mechanism. The basic principle of this newly proposed method was the composite action between steel and concrete. The straight and continuous steel bar was embedded in concrete to ensure no eccentricity that could interfere with research data due to the bending moment. 45 Specimens made from cylinder concrete with 101.6 mm diameter and 450 mm length, steel bar embedded at the center of the section. Three concrete mixes with actual compressive strength of 31.66 MPa, 40.27 MPa, and 46.60 MPa and steel bar diameters of 15.9 mm, 18.7 mm, and 21.7 mm were used as variables. The test was performed by applying an incremental tensile loading at both ends of the steel specimen with a load rate of 5-10 kN/minute to obtain a force-displacement relationship. The curve must be lessened with steel bar response to get the load-displacement of tension concrete, and then by dividing load with concrete area and displacement with the length of both LVDT can be generated stress-strain of tension concrete. This study shows that the tension-stiffening effect is affected by the reinforcement ratio. Where the reinforcement ratio increases, the tension-stiffening decreases. The steel bar to concrete-area ratio higher tends to more cracks. The concrete tensile strength of this research is taken from the stress of the first crack indicates very close to the direct tensile test but slightly higher. [ABSTRACT FROM AUTHOR]

In everyday life, concrete structures will certainly face rain, whereas rain in urban areas is rain that contains chemical substances such as water vapor, nitric acid, carbon, sulfuric acid, and salt. The effect that arises if the concrete is always exposed to acid rain is the reinforcement in the concrete that becomes rusty (corrosion) because the concrete will absorb acid rainwater for a certain time and cause the compressive strength of the concrete to decrease. This study aims to determine the effect of the use of crystalline technology in Xypex C-1000 added material to be used in concrete on the value of compressive strength, permeability, and resistance to sulfuric acid. In this research, the variation of concrete will be divided into normal concrete, 1.2% Xypex C-1000 concrete, and 0.6% Xypex C-1000 concrete. The highest compressive strength value with a concrete age of 28 days was found in the concrete variation with 1.2% Xypex C-1000 and the highest average compressive strength of concrete after soaking in 5% sulfuric acid was found in the concrete variation with 1.2% Xypex C-1000. It can be concluded that the use of Xypex C-1000 additives can increase the value of compressive strength, permeability, and resistance to sulfuric acid. [ABSTRACT FROM AUTHOR]

The process of hydrothermal carbonization, also known as HTC, is a thermochemical pretreatment method involving the utilization of heated, pressurized water to treat biomass and produce hydrochar. This research investigates the feasibility of using hydrochar produced from coconut fiber in concrete. It also evaluates the effect of HTC duration and the chemical treatment of coconut fiber on the qualities of concrete. Throughout the hydrothermal carbonization process, which usually lasts for 2, 3, and 4 hours, the temperature of 160 °C is kept constant. In this research, we utilized two types of coconut fiber: untreated coconut fiber and pretreated coconut fiber. The characteristics of the concrete, including its slump, dry density, compressive strength, and splitting tensile strength, were analyzed. The diameter of the sample is 10 cm, and it is 20 cm from top to bottom. The length of the HTC duration and the chemical treatment of the fibers have an influence on compressive strength, slump, and splitting tensile strength. On the other hand, they do not have an effect on the dry density. The highest slump was obtained at 4 hours of HTC processing for both types of fibers. The optimum compressive strength in concrete using untreated hydrochar is 28,43 MPa, but the greatest compressive strength using pretreated hydrochar is 25.16 MPa. Untreated hydrochar has the greatest compressive strength at 4 hours of HTC processing, while pretreated hydrochar has it at 2 hours of the HTC processing. In contrast, untreated hydrochar has the highest spliting tensile strength at 2 hours of the HTC processing, while pretreated hydrochar has it at 4 hours of the HTC processing. [ABSTRACT FROM AUTHOR]

The study aims to improve the thermal resistance of concrete by using natural fibre. In general, in Gulf countries, the solar heat is too high during the summer season, causing indoor heat in buildings. To combat this, air conditioners are used frequently, which is harmful to the environment and human health. Although there are many materials available to prevent heat at present, this study looked at how to effectively reduce heat indoors by using natural materials. This date palm fibre is a natural material that is widely available in the Gulf region, and it can be used to protect people from solar heat. The primary goal of the research is to determine the mechanical properties and thermal conductivity of concrete with various percentage of date palm fibre. The study discovered that when 0.2% date palm fibre is added to the concrete dosage, to have high thermal resistance and it was proved by the experimental study. Date palm fibre is added in concrete at 0% to 3% with a interval of 0.2%. (DPFRC) Date palm fibre reinforced concrete has excellent thermal resistance and compressive strength from test results. It will boost green energy technology in construction industry. [ABSTRACT FROM AUTHOR]

This article shows the results of a study to determine the rate and specific heat release of Portland cement grade PC-400 D20, the effect of temperature on the rate of heat release of cement stone. Research methods and a calorimeter diagram for determining the heat release of concrete during its hardening under isothermal conditions, the characteristics of the heat release of cement with additives and the kinetics of temperature changes during concrete hardening in molds are also given. The effect of the accelerating component of the complex additive, thiosulfate, on the value of the 1st exoeffect is small. This is due, first of all, to the fact that it compensates for the retarding effect of plasticizing components. A certain relationship is known between the degree of hydration and the heat release of concrete. Other things being equal, the dependence is directly proportional. [ABSTRACT FROM AUTHOR]

The main objective of the research was to compare the behavior of conventional concrete with the same concrete, but containing glass fibers. Ordinary concrete was adopted with mixing ratios (1:2.25:3) taken as a typical mixture from one of the ready-mix concrete factories, then 4 mixtures were made with different cement ratios, where the amount of cement was reduced and replaced with glass fibers, while keeping the weights of sand and coarse aggregate unchanged. The same water cement ratio (W/C) was used for all five mixtures. The results showed an improvement in the compressive strength of the concrete when using a certain limit of fibers. [ABSTRACT FROM AUTHOR]

Beams of reinforced concrete with flanges have been utilized extensively in a lot of applications in structural engineering. The total behavior of this type of member has been studied experimentally and analytically. In this paper, a finite element method-based numerical analysis was used to presented the reinforced concrete's behavior with flanges during the pre-and post-cracking level of loading up to their ultimate stress. Different types of flanged reinforced concrete beams were analyzed, and the results from finite element (F.E.M) were compared with experimental and analytical data. The impact of concrete's compressive strength has been examined. In general, excellent agreement has been obtained between the results of finite element and experimental tests. Also studied numerically is the distribution of concrete longitudinal compressive stresses and tensile stresses along the steel reinforcement. It is found that for high-strength concrete, the ACI Code 318M-14 underestimates the collapse moment of flanged reinforced concrete beams. [ABSTRACT FROM AUTHOR]